FDA explains in the draft guidance, titled ‘Technical Considerations for Non-Clinical Assessment of Medical Devices Containing Nitinol’, that nitinol is a commonly used material in the medical device industry, with device manufacturers using nitinol’s unique properties (i.e., pseudoelasticity and shape memory behavior) to design innovative medical devices that would not be possible with conventional materials.
Nitinol has been extensively used in cardiovascular devices such as stents, heart valves, guidewires, and vena cava filters. The use of nitinol in other device areas is growing, particularly for products intended for use in minimally invasive procedures. The thermomechanical behavior and processing sensitivity of nitinol raise special considerations when compared to conventional metals such as stainless steel, titanium, or cobalt-chrome alloys. Due to the unique properties of nitinol, the Agency has developed this draft guidance to provide FDA’s current thinking on technical considerations specific to devices using nitinol.
FDA further explains that these recommendations are intended to be general and not product-specific, and should be evaluated in conjunction with the intended use and technological characteristics of each individual device and any relevant device-specific guidance. The purpose of the draft is to outline technical considerations associated with medical devices that have at least one patient contacting component comprised of nitinol.
Comments on the draft are invited until 18 June 2019.